Love is an emotion. So, by definition, if you are merely “showing love”, you are faking it – and children see through our superficial acts.
If we want our children to love Hashem; Mitzvos; Torah – then we have to really love them – really feel it.
If we don’t, then it is our job to begin a project of improving our attitudes.
Too difficult? Don’t know how? Then we need to find the right Rebbe who can teach us properly.